While I can't say I know a lot about the Square Wheel, HardCore, Bader, or Burr King or any others except for what I have owned or used and I don't know really how they compare to each other, what I do know is this. When I was looking to get a new grinder I asked like 20 makers what they recommended and the KMG was the one the majority of them told me to go with. None of these others other than the BIII were even mentioned. More people mentioned and recommended Bob Dozier's machine than the BIII to me and it was still no where near all the guys saying KMG, KMG, KMG.
I bought the KMG. I can see quite clearly why so many told me to go with it. Its just my opinion but as far as bang for the buck goes I felt like the KMG just offered more than the others for less $. I bought mine and Adam Michael's MAP arm and still had less in it than the others were quoted to me before the MAP arm was added. Go figure. Again, I don't know much about the others. I'm sure they are nice in all the ways you guys mention. If there is a draw back to the KMG its the fact that its not stainless steel. I should have painted mine the day it arrived before assembly. Hindsight as they say is 20/20.
STR